<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #a{
            width: 70px;
            text-align: center;
            letter-spacing: 2px;
            font-style: italic;
            background-color: #ddd;
            border: 1px solid #000;
        }
    </style>
</head>
<body>

    <input type="text" placeholder="请输入验证码">
    <button>验证</button>
    <input type="text" name="" id="a" disabled value="1234">
    
    <button>刷新</button>
    
</body>
</html>